THE SUN AND STARS And anything I want to put in here.

STRUCTURE OF THE SUN  The sun is 93 million miles from earth, how do we know so much about it?  Scientist look at the sun’s light with a device called a spectrograph. Dark lines form in the spectra of stars when gases in the stars’ outer layers absorb specific wavelengths of the light that passes through the layers

 Each element present in the sun will produce a unique pattern of spectral lines. Scientist can use the lines to identify the elements in the stars atmosphere

 The sun’s mass is about 99% hydrogen and helium, as a matter of fact, all stars contain hydrogen and helium

THE SUN’S INTERIOR  The sun’s interior can not be seen by scientist, but computer models have revealed possibly what it would be like. Using information from the surface, scientist can deduce what must be happening inside to produce such effects.

 Three parts to the sun’s interior: core, radiative zone and convective zone.

CORE  Diameter: 1,390,000 km  Temperature: 15,000,000 0 C  Mass: 300,000 times greater than earth  Core is so dense with ionized gases you could stand on it  Because of the high temperature and pressure, nuclear reaction occur, nuclear fusion.

RADIATIVE ZONE  Energy from the core is radiated to this zone.  Temperature ranges form 2,000,000 0 C to 7,000,000 0 C  Energy moves outward in the form of eletromagnetic waves called radiation.

CONVECTIVE ZONE  Energy that is produced in the core moves through this zone by convection  Carries hot gases to the surface of the earth  Temperature: 2,000,000 0 C  Gases rise and sink because they cool as they move to the sun’s surface.

THE SUN’S ATMOSPHERE  Although the sun is made of gases, the term atmosphere refers to the uppermost region of the solar gases. This region has 3 layers: photosphere, chromosphere, and the corona.

PHOTOSPHERE  The innermost layer of the solar atmosphere is the photosphere  Temperature: 6,000 0 C  Part visible from earth, gives off visible light  Has sunspots

CHROMOSPHERE  Chromosphere lies above the photosphere.  Temperature: 4,000 to 5,000 0 C  Glows reddish, gases move away from the photosphere  Gases of the chromosphere will shot out

CORONA  The corona is the outermost layer of the sun’s atmosphere.  Temperature: 1,000,000 0 C  Only visible during an eclipse  Escaping particles, ion, blow away forming the solar wind.

ASSIGNMENT  Go to Page 758  Sketch and label the drawing.

HOW THE SUN GET ENERGY  A powerful atomic process know as nuclear fusion occurs inside the sun. Because of the high temperature and pressure, nuclei are opened and particles are changed and energy is released

 Step1: Two hydrogen nuclei or protons, collide and fuse. ( the positive charge of one of the protons is neutralized as that proton emits a particle called a positron. As a result, the proton becomes a neutron and changes the original two protons into a proton neutron pair.

 Step2: Another proton combines with this proton neutron pair to produce a nucleus made up of 2 proton and one neutron.  Step 3. two nuclei made up of two protons and one neutron collide and fuse

 As this fusion happens, two protons are released. The remaining two protons and two neutrons are fused together and form a helium nucleus and energy is releases  Go to Page757 for mini lab explaining the process 

MASS CHANGING INTO ENERGY  Only 70% of the mass of the hydrogen is converted to helium during nuclear fusion. What happens to the 30% left? It is changed into energy. Remember…Matter is neither created or destroyed.

 In 1905, Albert Einstein proposed an explanation for the production of energy. The theory become knows as Relativity.  E = mc 2 Where E is energy, m is mass and c 2 is the speed of light.

CALCULATIONS  Mass of 6 hydrogens =   Mass of helium=  =

CALCULATIONS  E =2.040 x186,000 2 = bazillion X 10 7  This is the energy made. Millions of atoms are converted per second producing tons of energy. The number above is for only one Helium being produced. #WOW!

SOLAR ACTIVITY  The sun is a ball of hot gases rather than a solid sphere, not all locations on the sun rotate at the same speed. Places close to the equator on the surface of the sun take 25.3 earth days to rotate once. On average, the sun rotates once every 27 days.

SUNSPOTS  The movement of gases within the convective zone and the movements caused by the sun’s rotation produce magnetic fields. There magnetic fields

 Cause convection to slow in parts of the convective zone. Slower convection produces cool areas. The cooler areas of the sun appear darker and are called sunspots.

 Sunspot activity appears to follow an 11 year cycle, slowing increasing then decreasing their numbers.

SOLAR EJECTIONS  Because of the continuing changes in the magnetic field, there are 3 types of solar ejections produced: prominences, solar flares and coronal mass ejections.

PROMINENCES  Great clouds of glowing gases, called prominences, form huge arches that reach high above the sun’s surface. Each arch follows curved lines of magnetic force from a region of opposite polarity to another.

SOLAR FLARES  The most violent of all solar disturbances is a solar flare, a sudden outward eruption of electrically charged particles, such as electrons and protons

 Solar flares release the energy stored in the strong magnetic fields of sunspots. During peak of sunspot activity, there may be 5-10 sunspots a day

CORONAL MASS EJECTIONS  Coronal mass ejections are parts of the corona thrown off by the sun. CME’s are full of electrons

 Which interact with the earth’s magnetosphere. This produces geomagnetic storms, which can interfere with radio communication and power lines

AURORAS  A spectacular effect occurs between the solar wind and Earth’s magnetosphere – Aurora. The electrically charged particles from the

 Solar winds interact with earths magnetic field. The electrons strike the gases in the atmosphere and produce beautiful dancing light